Conic section activity boards

Abstract

The present invention provides a variety of laminated plastic activity boards that allow the individual to visualize and have interactive exploration of conic sections and their definitions. This allows for more class time to be spent investigating the concept of conic sections opposed to teachers lecturing and the students having to memorize them. The user is able to notice patterns which develop while drawing specific sets of conic sections by forming conjectures based on the observed outcomes of the activities. Each activity board has a reusable laminated surface which allows the ink used from a marker to be visible but not permanent. The surface can be wiped clean with a moist paper towel once the activity is completed. There are a total of four activity boards which operate independently of each other and contain different concepts. The four boards teach principles relating to the circle, ellipse, parabola and hyperbola. On the underside of the circle and eclipse activity boards is a string container which features a release and a retraction bar. By pressing the desired bar, the string will either be released or contracted. The string is pulled through a hole in the board and extended to a desired length for use on the activity side. The underside of the parabola and hyperbola activity boards carries a sliding tray that acts to pivotally secure a ruler in one of a number of aligned openings.

What is claimed is:  
     
       1. A conic section activity board, comprising: 
       a planar board having an erasable upper surface, a lower surface, and an opening formed through a central portion of the board between the upper and lower surfaces;  
       a string disposed to extend from the lower surface, through the opening, and over the upper surface a predetermined distance, the string having a lower end attached to a dispensing mechanism and an upper end attached to a marker holder; and  
       a marker disposed to be received in the marker holder and being selectively movable over the board to circumscribe a closed region.  
     
     
       2. The activity board of claim  1  wherein the closed region defines a circle having a radius of the predetermined distance. 
     
     
       3. A conic section activity board, comprising: 
       a planar board having an erasable upper surface, a lower surface, and an opening formed through a portion of the board between the upper and lower surfaces;  
       a magnetic strip attached to the lower surface of the board and extending from the opening in a line laterally across the board;  
       a string disposed to extend from the lower surface, through the opening, and over the upper surface a predetermined distance, the string having a lower end attached to a dispensing mechanism and an upper end attached to a metal disc, the metal disc being selectively secured to the upper surface of the board along the lateral line by the magnetic strip;  
       a single string having one end attached to the string and being movable between the opening in the board and the metal disc, the single string having another end attached to a marker holder; and  
       a marker disposed to be received in the marker holder and being selectively movable over the board to circumscribe a closed region.  
     
     
       4. The conic section activity board of claim  3  wherein the closed region defines an ellipse having a first focus at the opening in the board and a second focus at the metal disc. 
     
     
       5. A conic section activity board, comprising: 
       a planar board having an erasable upper surface, a lower surface, and a plurality of aligned openings formed through a portion of the board between the upper and lower surfaces;  
       a first ruler having one end pivotally attached to one of the plurality of aligned openings;  
       a raised guide attached to the upper surface of the board and disposed perpendicular to the plurality of aligned openings;  
       a second ruler having one end movably attached to the guide, and being disposed to extend parallel to the plurality of aligned openings; and  
       a marker selectively disposed to mark the upper surface of the board at a plurality of points where the first and second rulers intersect at lengths of a predetermined ratio, whereby connecting the marked points defines a parabola.  
     
     
       6. A conic section activity board, comprising: 
       a planar board having an erasable upper surface, a lower surface, and a plurality of aligned openings formed through a portion of the board between the upper and lower surfaces;  
       a first ruler having one end pivotally attached to one of the plurality of aligned openings;  
       a second ruler having one end pivotally attached to another of the plurality of aligned openings; and  
       a marker selectively disposed to mark the upper surface of the board at a plurality of points where the first and second rulers intersect at lengths of a predetermined length differential, whereby connecting the marked points defines a hyperbola.